The present invention relates to an electromagnetic wave transmission line for use in an integrated circuit (IC) or the like and, in particular, relates to a transmission line which exhibits superior transmission characteristics, particularly, in transmitting microwave or millimeterwave, and to a transmission line provided with integral circuit elements formed by partially deforming the line itself.
The conventional transmission line for microwave transmission has utilized a coaxial line, a rectangular waveguide or a circular waveguide. Further, there has recently been developed an integrated device utilizing active and passive microwave elements. In such derive the respective elements are connected to a micro-strip line or a transmission line having sandwitch construction composed of an n-type semiconductor layer with high doping concentration, an ohmic electrode and an n-type semiconductor layer with very low doping concentration sandwitched therebetween.
All conventionally proposed transmission lines are, however, passive and, therefore, once the parameters of the line are determined, it is difficult to change them by externally applied signals. Furthermore, conventional transmission lines have the disadvantage that line loss increases with increasing frequencies.
One object of the present invention is to overcome the disadvantages inherent in the conventional transmission line by providing a novel transmission line for electromagnetic wave which is lossless or even has amplification characteristics at any given frequency.
Another object of the present invention is to provide a transmission line which by partial deformation of the transmission line itself is provided with such integral circuit elements as a capacitance element, an inductance element, a resistive element or a switching element, amplifying element, oscillation element, amplitude modulation element, etc., singularly or in combination.